The present invention relates to a catalytic element comprising a porous ceramic body useful for promoting catalytic gas phase reactions in general and for reforming hydrocarbon or tar compounds containing feed gas in particular.
Catalytic elements of the afore-mentioned type are often used in catalytic gas phase reactions where the catalytic elements are operated under severe operating conditions, especially high temperatures like 700° C. or above, high fluid flow rates and quite often a substantial load of particulate contaminants within the gaseous fluid to be treated.
A catalytically active porous element for promoting catalytic gas phase reactions with a specific focus on NOX reduction is disclosed in WO 2006/037387 A1. The porous body of such catalytically active porous elements comprises a porous structural element of sintered ceramic or metallic primary particles which are selected from fibers and/or granular particles, a secondary structure of titanium dioxide nanoparticles deposited on the surface of said sintered primary particles and a catalytic component deposited on the surface of the titanium dioxide nanoparticles. Although these elements give excellent results in NOX reduction and a number of other catalytic gas phase reactions, they do not support reforming reactions of hydrocarbons or tar compounds in feed gases like syngas or crude natural gas.
Another type of a porous ceramic body with an open-celled structure for catalytic elements has been suggested in U.S. Pat. No. 3,090,094. Some of the ceramic bodies described in this patent were tested as catalyzer for the oxidation of unburned hydrocarbons in vehicle engine exhaust gas.
These ceramic bodies may not successfully be used for other types of catalytic gas phase reactions, in particular for reforming of tar compounds or hydrocarbons in a feed gas.
Therefore, the object of the present invention is to provide a catalytic element comprising a porous body which may be used in a broad variety of catalytic gas phase reactions, especially under severe operating conditions.